1. Field of the Invention
The present invention relates to an airbag device for front passenger's seat to be mounted on the instrument panel (as will be called “dashboard” hereinafter) in front of a front passenger's seat.
2. Description of Related Art
Conventionally, an airbag device for front passenger's seat includes an airbag, an inflator for supplying the airbag with inflation gas, a case for holding the airbag and the inflator, and an airbag cover for covering the folded airbag.
As an inflator, a disc-type is used, for example, as disclosed in Japanese Patent Laid-Open No. Hei 9-86319. This disc-type inflator includes a cylindrical body and a flange projected from the outer circumference of the body for the attachment to the case. The body is provided on the upper outer surface above the flange with a plurality of gas discharge ports for discharging the inflation gas.
The case has a bottom wall with an insert hole large enough to insert the upper portion of the inflator with the gas discharge ports therein toward the inner space of the case.
The airbag has an opening for admitting the inflation gas. The airbag is secured to the bottom wall of the case by means of an annular retainer, which is pressed on the periphery of the opening and attached to the bottom wall of the case.
Moreover, the inflator in the above disclosure is a pyro-type which generates inflation gas by chemical reaction such as burning reaction of gas generating material. The pyro-type inflator is favorably used for a vehicle because of its compactness, compared with a hybrid type inflator charged with inflation gas.
However, the conventional pyro-type inflator has a room for improvement in the timing of supplying the inflation gas to the airbag for front passenger's seat.